1. Field of the Invention
The field of the invention relates to photon sources for use in, for example, quantum information processing applications.
2. Description of the Related Art
Single photon sources are useful devices for quantum information processing applications, including, for example quantum computing and quantum cryptography. In the past, optical sources that emit very weak pulses have been used to attempt to generate single photons on demand. A difficulty associated with such devices is that the statistical properties associated with their photon emission results in a relatively large amount of uncertainty as to the precise moment that a photon will be emitted. There is also a relatively large window of time following a demand for production of a photon in which the photon may actually be emitted.
Moreover, attempts to reduce the delay between the time a photon is demanded and the time it is emitted, for example to increase the rate at which photons can be provided, can increase the probability of delivering multiple photons at a time instead of a single photon. Thus, maintaining the probability of multiple photon generation below an acceptable threshold may require longer intervals between generated photons and, hence, slower clock rates. There is an inverse relationship between the rate at which these devices are operated and their ability to effectively provide single photons on demand. There remains a need for improved single photon sources.